Semiconductor apparatus including a tin barrier layer having a (III) crystal lattice direction

ABSTRACT

A semiconductor apparatus having at least a compound film containing nitrogen and a method for production of the same, wherein the compound film containing nitrogen is formed under conditions where the ratio of the flow rates of the nitrogen with respect to an inert gas is 0.125 to 1.0.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor apparatus and a methodof producing the same, more particularly, relates to a compound filmcontaining nitrogen (for example, a TiN film) used for example as abarrier film in a contact portion between an interconnection layer and asemiconductor or a contact portion between one interconnection layer andanother interconnection layer.

2. Description of the Related Art

The increasing miniaturization of semiconductor devices has led togreater demands on the reliability of interconnections. Particularly,the metal using for forming a film so as to give an ohmic-contact withrespect to a shallow junction of a transistor and the underlying silicon(Si) are brought into close contact by a boundary reaction so as to givea good electrical connection. If the reaction is excessively advanced,however, the metal penetrates through the shallow junction portion tocause a large junction leakage. Conversely, if the reaction isinsufficient, there is a problem in that the ohmic-contact is notobtained and therefore the electrical characteristics become unstable.

Here, an example of a process for producing a conventional metal oxidesemiconductor (MOS) large-scale integrated circuit (LSI) will beexplained with reference to FIGS. 1A to 1C.

(a) As shown in FIG. 1A, an element isolation region (LOCOS) 4, a gateinsulation film 6, a gate electrode 8, and a source-drain region 10 areformed on the surface of a semiconductor substrate 2 to form an MOStransistor.

(b) Next, as shown in FIG. 1B, an interlayer insulation film 12 isformed on the MOS transistor, and a contact hole 14 is formed in this.

(c) Next, as shown in FIG. 1C, blanket tungsten 16 or the like is filledin the contact hole 14. Further, a film of an aluminum (Al)-based alloy17 such as Al--Si is formed on this and subjected to patterning so as toform an interconnection region.

While the element is formed by the example of the production processdescribed in the above steps (a) to (c), the interconnections and thesilicon substrate (Si) have been connected using a laminate structure ofsilicon nitride and titanium (TiN/Ti). However, if the reaction of theTi is insufficient, a good ohmic-contact is not obtained and a problemoccurs.

As a method of keeping the reaction between the interconnection metaland the underlying silicon from being obstructed, use has been made of aTiN film. By forming a TiN film with (a good barrier property, thecontact characteristics can be stabilized. However, it has been not beenpossible to control the change in the film quality with respect to theparameters of the method of forming the TiN film. Therefore, at thepresent time, it is not possible to produce a device with the best filmquality.

Also, recently, a technique of forming a film of TiN by collimatesputtering has been developed. Collimate sputtering is a technique wherea collimate is disposed between the target of the sputtering apparatusand the wafer and sputtering particles of an oblique direction are madeto deposit on it, whereby only particles in the vertical direction andin directions close to this are taken out, thereby improving the bottomcoverage rate of the contact holes.

In this collimate sputtering, generally, the flow rate of the nitrogengas with respect to the argon gas was as high as 1.5 or more. Also, inthis collimate sputtering, it was impossible to control the changes inthe film quality with respect to the parameters of the method of formingthe TiN film. Therefore, at the present time, it is not possible toprepare a device with the best film quality.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a structure and amethod of producing a film suitable for use as a barrier film or thelike used as a film underlying an interconnection layer.

The present invention provides a method of production which enablescontrol of the reactivity with the underlying silicon and control of thedirection of an interconnection metal on the TiN (controlling thedirection of the interconnection metal enabling improvement of theelectrical migration, that is, the reliability of interconnections) anda connection structure using the same.

It has been known that the reaction for forming TiSi₂ depends stronglyupon the crystal lattice direction of the titanium formed. In the casewhere the Ti formed has a (002) lattice direction, it has been confirmedby experiments that the reactivity with the underlying silicon becomesstrong.

Therefore, the present invention adopts as a contact structure astructure wherein Ti of a (002) lattice direction having a strongreactivity is connected to the silicon so as to enable control of theparameter of the film thickness of the Ti (002) crystal and control ofthe film thickness of the silicide formed.

As the method of controlling the Ti (002) lattice direction, there arethe methods of changing the sputtering power, bias sputtering, etc. Inthis method of production, various types of contact structures can beobtained by continuously changing the power during the sputtering. FIG.5 shows the Ti and TiN which are easily oriented.

Also, it is clear that it is possible to control the quality of the TiNfilm formed by controlling the flow rate of the nitrogen gas in thesputtering gas as the method of controlling the direction of the Ti.

The present inventor examined the resistivity and density of TiN byvarying the flow rate of the nitrogen gas with respect to the flow rateof the argon gas and consequently found that the resistivity and densityof the TiN film changed together with the change of the flow rate ofnitrogen as shown in FIG. 2. FIG. 3 is a view of the results of asimilar examination of the dependency of the speed of film formation onthe flow rate of the nitrogen gas. From these states, a mode where thenitrogen flow rate is 20 sccm or less (N₂ /Ar≦0.5) is called a metallicmode, and a mode where it is 30 sccm or more (N₂ /Ar≦0.75) is called anitride mode. It is seen that, in the case of the metallic mode, notonly is the resistivity low and the film density high, but also, asshown in FIG. 4, the crystals are strongly oriented in the TiN (111)since the half-value width of the TiN (111) lattice direction is narrowas seen from the results of X-ray diffraction analysis (XRD). Moreover,it was confirmed that the composition was one where the titanium andnitrogen were closer to the stoichiometric state (it can be said that astate where the ratio of Ti and N is near 1.0 is TiNstoichiometrically).

A preferred aspect of the semiconductor apparatus according to thepresent invention will be shown below.

A semiconductor apparatus according to the present invention is asemiconductor apparatus having at least a compound film containingnitrogen. The aforesaid compound film containing the nitrogen is formedunder conditions such that the ratio of the flow rates of the nitrogenwith respect to the inert gas is from 0.125 to 1.0.

Preferably, the aforesaid compound film containing the nitrogen isformed by reactive sputtering or chemical vapor deposition (CVD).

Preferably, the aforesaid compound film containing the nitrogen is TiN,WN, MoN, ZrN, HfN, BN, CN, or oxides of any of these, furtherpreferably, TiN.

Preferably, the aforesaid inert gas is an argon gas.

Preferably, the interconnection layer and the semiconductor of thesemiconductor apparatus are electrically connected through the contactportion, and the underlying film disposed between the aforesaidinterconnection layer and the semiconductor contains at least theaforesaid compound film containing the nitrogen.

Preferably, the aforesaid compound film containing the nitrogen acts asa barrier film in the aforesaid contact portion.

Preferably, the aforesaid underlying film has a Ti film in contact withthe semiconductor and a TiN film laminated on this Ti film.

It is also possible to constitute the aforesaid underlying film by theTi film in contact with the semiconductor, a first TiN film laminated onthis Ti film, and a second TiN film laminated on this first TiN film andhaving different characteristics from those of the first TiN film.

Preferably, the crystal lattice direction of the aforesaid Ti film is(002) and the crystal lattice direction of the aforesaid first TiN filmis (111).

It is also possible to constitute the aforesaid underlying film by a Tifilm in contact with the semiconductor and having a crystal latticedirection of (002) and a TiN film laminated on this Ti film and having acrystal lattice direction of (111).

It is also possible to constitute the aforesaid underlying film by a Tifilm in contact with the semiconductor and having a crystal latticedirection of (002), a TiN film laminated on this Ti film and having acrystal lattice direction of (111), and a TiON film laminated on thisTiN film.

Preferably, a lower interconnection layer and an upper interconnectionlayer of the semiconductor apparatus are electrically connected throughthe contact portion, laminate films are laminated on the aforesaid lowerinterconnection layer, and the laminate film contains at least theaforesaid compound film containing the nitrogen.

Preferably, the film positioned in the uppermost layer among theaforesaid laminate films acts as an anti-reflection film when subjectingthe aforesaid lower layer interconnection to photolithography.

Preferably, the aforesaid laminate film has a TiN film in contact withthe lower interconnection layer, and a TiON film laminated on the TiNfilm.

Preferably, the crystal lattice direction of the aforesaid TiN film is(111).

It is also possible to constitute the aforesaid laminate film by a Tifilm in contact with the lower interconnection layer, a TiN filmlaminated on the Ti film, and a TiON film laminated on the TiN film.

Preferably, the crystal lattice direction of the aforesaid Ti film is(002) and the crystal lattice direction of the aforesaid TiN film is(111).

It is also possible to constitute the aforesaid laminate film by a Tifilm in contact with the lower interconnection layer, a first TiN filmlaminated on the Ti film, and a TiN film laminated on the first TiN filmand having different characteristics from those of the first TiN film.

When continuously forming the aforesaid first TiN film and second TiNfilm by the reactive sputtering, preferably the ratio of the flow rateof the nitrogen gas with respect to the inert gas is changed.

Preferably, the ratio of the flow rates of the nitrogen gas with respectto the inert gas at the time of formation of the aforesaid first TiNfilm is controlled to 0.7 or less, more preferably 0.5 or less, and theratio of the flow rates of the nitrogen gas with respect to the inertgas at the time of formation of the aforesaid second TiN film iscontrolled to 0.75 or more, more preferably 1.0 or more.

The aforesaid TiON film can be formed by forming, by reactivesputtering, the aforesaid TiN film with a ratio of the flow rates of thenitrogen gas with respect to the inert gas of 1.0 to 0.125, and thenchanging the ratio of the flow rates of the nitrogen gas with respect tothe inert gas to the larger side to form a rough TiN film, then exposingthis rough TiN film to the atmosphere or a low vacuum atmosphere havinga divided pressure of oxygen of 0.1 Pa or more so as to change the roughTiN film to a TiON film.

It is also possible to form the aforesaid TiON film by reactivesputtering using the nitrogen gas, oxygen gas, and inert gas.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention willbecome clear from the following description of the preferred embodimentsmade with reference to the accompanying drawings, in which

FIGS. 1A to 1C show an example of a process for producing a conventionalmetal oxide semiconductor (MOS) large-scale integrated circuit (LSI);

FIG. 2 shows the relationship between the resistivity and density of aTiN film and the change of the flow rate of nitrogen;

FIG. 3 shows the dependency of the speed of film formation on the flowrate of the nitrogen gas;

FIG. 4 shows the dependency of the FWMH of the TiN (111) lattice on theflow rate of the nitrogen gas;

FIG. 5 shows Ti (002) lattice direction crystals;

FIGS. 6A to 6D show an example of a process for producing a metal oxidesemiconductor (MOS) device according to the present invention;

FIG. 7 shows an alternative step in the process for producing a metaloxide semiconductor (MOS) device according to the present invention;

FIGS. 8A to 8C show another example of a process for producing a metaloxide semiconductor (MOS) device according to the present invention;

FIG. 9 shows the relationship of the reflection rate and the wavelengthof light.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Below, embodiments of the present invention will be explained in detailusing the drawings.

First, an explanation will be made of the first embodiment of thepresent invention.

The present embodiment is a method for controlling the gas flow rate.First, use is made of a magnetron sputtering apparatus having a Titarget. Argon is passed to form a film having a Ti (002) latticedirection. Thereafter, the nitrogen is introduced to form a TiN film. Atthis time, a ratio of the flow rate of Ar/N₂ =40/20 sccm is set. Bythis, a high density, stoichiometric TiN film having a TiN (111) latticedirection can be formed.

Below, a detailed explanation will be made of an embodiment wherein thepresent invention is applied to the MOS device process with reference tothe drawings.

(a) As shown in FIG. 6A, a MOS transistor is formed on the surface of asemiconductor substrate 22 by forming an element isolation region(LOCOS) 24, a gate insulation film 26, a gate electrode 28 and asource-drain region 30.

(b) Next, as shown in FIG. 6B, an interlayer insulation film 32constituted by for example SiO₂ is formed.

An example of the conditions for formation of the interlayer insulationfilm 32 by CVD will be shown next.

EXAMPLE 1

Gas TEOS=50 sccm

Temperature: 720° C.

Pressure: 40 Pa

Film thickness: 600 nm

After forming the interlayer insulation film 32, resist patterning iscarried out to form a contact hole 34.

An example of the etching conditions for forming the contact hole 34will be shown next.

EXAMPLE 2

Gas C₄ F₈ =50 sccm

RF power: 1200 W

Pressure: 2 Pa

(c) Next, an interconnection material is formed as shown in FIG. 6C.

The contact hole 34 is filled with blanket tungsten (W) 36.

First, the TiN/Ti, which is the tungsten-close contact layer(tungsten-underlying film), is formed.

An example of the conditions for forming the Ti film 38 by sputteringwill be shown next.

EXAMPLE 3

Power: 8 kW

Film formation temperature: 150° C.

Ar: 100 sccm

Film thickness: 10 nm

Pressure: 0.47 Pa

Under these film formation conditions, the Ti (002) lattice directioncrystal shown in FIG. 5 can be formed.

An example of the conditions for forming the TiN film 40 which is formedon the Ti film 38 by sputtering will be shown next.

EXAMPLE 4

Power: 5 kW

Gas Ar/N₂ =40/20 sccm

Pressure: 0.47 Pa

Film thickness: 70 nm

The TiN film 40 formed under such conditions (ratio of the flow rates ofN₂ with respect to Ar of about 0.5) has a lattice direction crystal(111) as shown in FIG. 5, and, as shown in FIG. 2, has a high densityand low resistivity.

An example of the conditions for formation of the tungsten on the TiNfilm 40 by CVD will be shown next.

EXAMPLE 5

Gas Ar/N₂ /H₂ /WF₆ =2200/300/500/75 sccm

Temperature: 450° C.

Pressure: 10640 Pa

Film thickness: 400 nm

Next, the tungsten is etched back, and a blanket tungsten 36 is formed.An example of the etching back conditions of the tungsten will be shownnext.

EXAMPLE 6

Gas SF₆ =50 sccm

RF power: 150 W

Pressure: 1.33 Pa

(d) Next, as shown in FIG. 6D, the interconnection of Al/Ti is formed.

First, a Ti film 42 is formed. An example of the conditions for formingthe Ti film 42 by sputtering will be shown next.

EXAMPLE 7

Power: 4 kW

Film formation temperature: 150° C.

Ar=100 sccm

Film thickness: 30 nm

Pressure: 0.47 Pa

Next, the Al film 37 is formed on the Ti film 42. An example of theconditions for forming the Al film 37 by sputtering will be shown next.

EXAMPLE 8

Power: 22.5 kW

Film formation temperature: 150° C.

Ar=50 sccm

Film thickness: 0.5 μm

Pressure: 0.47 Pa

Thereafter, an Al/Ti interconnection layer is formed by resistpatterning and dry etching. An example of the etching conditions will beshown next.

EXAMPLE 9

Gas BCl₃ /Cl₂ =60/90 sccm

Microwave power: 100 W

RF power: 50 W

Pressure: 0.016 Pa

Next, an explanation will be made of a second embodiment of the presentinvention.

In the second embodiment, the same procedures as those for the firstembodiment are carried out except the Ti film 38 and TiN film 40 of thefirst embodiment are formed by using collimate sputtering.

The following explanation will be made only of portions different fromthe first embodiment.

(c) TiN/Ti is formed. In this case, it is formed by a magnetronsputtering apparatus to which a collimate is attached.

First, the Ti film 38 is formed. An example of the conditions forforming the Ti film 38 will be shown next.

EXAMPLE 10

Power: 8 kW

Film formation temperature: 400° C.

Ar: 100 sccm

Film thickness: 20 nm

Pressure: 0.47 Pa

An example of the conditions for forming the TiN film 40 on the Ti film38 will be shown next.

EXAMPLE 11

Power: 5 kW

Gas Ar/N₂ =40/20 sccm

Pressure: 0.47 Pa

Film thickness: 100 nm

By performing the collimate sputtering method under such conditions, theTiN film 40 having a TiN (111) lattice direction shown in FIG. 5 isformed. This TiN film 40 has a high density and low resistivity as shownin FIG. 2.

Next, an explanation will be made of a third embodiment of the presentinvention.

The third embodiment is an embodiment similar to the aforesaid firstembodiment except that the step shown in FIG. 6C is changed to the stepshown in FIG. 7.

Explaining the third embodiment in brief, at the time of the formationof TiN, a high density TiN (111) crystal is formed in advance with Ar/N₂=40/20 sccm. Thereafter, it is continuously changed to Ar/N₂ =40/70 sccmto form a rough TiN film. Oxygen is stacked on that part to make onlythe surface portion TiON and thereby give a double layer structure tothe barrier metal.

The present embodiment will be explained in further detail below.

(c) TiN/Ti is formed.

First, as shown in FIG. 7, a Ti film 44 is formed. An example of theconditions for formation of the Ti film by sputtering will be shownnext.

EXAMPLE 12

Power: 2 kW

Film formation temperature: 150° C.

Ar: 100 sccm

Film thickness: 20 nm

Pressure: 0.47 Pa

A TiN film 46 is formed on the Ti film 44. An example of the conditionsfor formation of the TiN film 46 by sputtering will be shown next.

EXAMPLE 13

Power: 5 kW

Gas Ar/N₂ =40/20 sccm

Pressure: 0.47 Pa

Film thickness: 40 nm

Further, the ratio of the flow rates of the Ar/N₂ gas is continuouslychanged to form the TiN. An example of the conditions for formation ofthe film will be shown next.

EXAMPLE 14

Power: 5 kW

Gas Ar/N₂ =40/70 sccm

Pressure: 0.47 Pa

Film thickness: 10 nm

The TiN film formed under these film formation conditions has a ratio ofthe flow rates of Ar/N₂ =40/70 sccm, and therefore, as shown in FIG. 2,the density is low in comparison with the TiN film which is formed witha gas Ar/N₂ =40/20 sccm.

By ejecting the semiconductor substrate 22 from the sputtering chamberof the apparatus into the atmosphere, oxygen is stacked on the rough TiNsurface to form a TiON film 48.

In the present embodiment, the barrier metal has a double structure, sothe barrier property is improved.

Next, an explanation will be made of the fourth embodiment of thepresent invention.

The fourth embodiment is an example of use for an anti-reflection filmfor preventing halation in lithography of the interconnection layer.

A high density TiN (111) crystal is formed in advance on theinterconnection layer with an Ar/N₂ =40/20 sccm. Thereafter, the ratiois continuously changed to Ar/N₂ =40/70 sccm to form a rough TiN filmand oxygen is stacked on that part to give a structure wherein only thesurface portion is changed to TiON. The rough TiN film is changed toTiON just by conveyance in the apparatus. When the interlayer insulationfilm is formed on this, a contact hole is formed in this interlayerinsulation film, and a plug of Al, W or the like is formed in thecontact hole, a strong TiN is formed under the TiON, therefore themovement of the inflowing Al or the like to or from the upper layerinterconnection from the lower layer interconnection through the plugalong with heat treatment can be prevented.

Also, TiON having a higher anti-reflection effect than that of TiN isused as the anti-reflection film, and therefore there is the advantagethat the precision of processing of the interconnections is improved.

An example wherein the method of the present invention is concretelyapplied to an MOS transistor will be shown next.

(a) First, as shown in FIG. 8A, the interconnection of Al/Ti is formedon the underlying substrate 49. The underlying substrate 49 is forexample the lower layer interlayer insulation film.

An example of the conditions for formation of the Ti film 50 on theunderlying substrate 49 will be shown next.

EXAMPLE 15

Power: 4 kW

Film formation temperature: 150° C.

Ar=100 sccm

Film thickness: 30 nm

Pressure: 0.47 Pa

An example of the conditions for formation of the Al film 52 on this Tifilm 50 by sputtering will be shown next.

EXAMPLE 16

Power: 22.5 kW

Film formation temperature: 150° C.

Ar=50 sccm

Film thickness: 0.5 μm

Pressure: 0.47 Pa

Next, a TiN film 54, which becomes the barrier metal of the upper layerinterconnection and becomes the anti-reflection film for thelithography, is formed on the Al film 52. An example of the conditionsfor forming the TiN film 54 by sputtering will be shown next.

EXAMPLE 17

Power: 5 kW

Gas Ar/N₂ =40/20 sccm

Pressure: 0.47 Pa

Film thickness: 20 nm

Further, the ratio of the flow rates of the Ar/N₂ gas is continuouslychanged to form the TiN film on the TiN film 54 by reactive sputtering.An example of the conditions for formation of the film will be shownnext.

EXAMPLE 18

Power: 5 kW

Gas Ar/N₂ =40/70 sccm

Pressure: 0.47 Pa

Film thickness: 10 nm

By exposing the TiN film to the atmosphere in this state, oxygen isstacked on the rough TiN surface to change it to a TiON film 56.Thereafter, resist patterning and dry etching are carried out to formthe Al/Ti interconnection layer. An example of the etching conditionswill be shown next.

EXAMPLE 19

Gas BCl₃ /Cl₂ =60/90 sccm

Microwave power: 1000 W

RF power: 50 W

Pressure: 0.016 Pa

At this time, the TiON film 56 is formed on the interconnections, andtherefore, at the time of exposure, the generation of halation issuppressed, and stable patterning becomes possible. FIG. 9 shows theanti-reflection effect by the TiON film. Due to the TiON film, it ispossible to minimize the reflection rate with respect to light having aspecific exposure wavelength, and the generation of halation at the timeof exposure can be prevented. Note that, in FIG. 9, the film thicknessof the TiON film was set to 300 angstroms, but the curve of FIG. 9 canbe shifted to the left side along with an increase of the filmthickness.

(b) Next, as shown in FIG. 8B, the interlayer insulation film 58 on theupper layer side is formed. An example of the conditions for formationof the interlayer insulation film 58 by CVD will be shown next.

EXAMPLE 20

Gas TEOS=50 sccm

Temperature: 720° C.

Pressure: 40 Pa

Film thickness: 600 nm

Next, the resist patterning is carried out to form the contact hole 60in the interlayer insulation film 58. The dry etching conditions forforming that contact hole will be shown next.

EXAMPLE 21

Gas C₄ F₈ =50 sccm

RF power: 1200 W

Pressure: 2 Pa

In this case, it is also possible to form the contact hole 60 so thatthe TiON film 56 serving as the anti-reflection film is left withoutetching, or, as shown in FIG. 8B, it is also possible to form thecontact hole 60 so that the etching is carried out up to the TiON film56 serving as the anti-reflection film and the surface of the TiN film54 is exposed.

Note, when considering the electrical conductivity, the latter case(FIG. 8B) is preferable and the manufacturing yield is improved.

(c) Further, as shown in FIG. 8C, the Al/Ti interconnection layer isformed. The film formation conditions are omitted since they are almostthe same as those described above. Next, the interconnection region isformed by resist patterning and dry etching. These conditions are alsothe same as those described above, and therefore no explanation isgiven.

In this construction, the TiN film serving as the barrier metal existsin the upper portion of the lower layer interconnection, wherebymovement of Al accompanied with the reaction in the via-contact(via-con) connection portion is no longer caused in the heat treatmentafter this during the process since the TiN suppresses the reactionbetween the lower layer interconnections and the upper layerinterconnections. For this reason, interconnection voids are suppressed,and an element having an improved reliability of interconnections isobtained.

Next, an explanation will be made of a fifth embodiment of the presentinvention.

In the fifth embodiment, the procedures are the same as those for theaforesaid fourth embodiment except that, when forming a further roughTiN film which serves as the TiON film 56 of the fourth embodiment,oxygen gas is introduced so that the TiON is continuously formed.

The present invention is not restricted to the above-describedembodiments. There is no problem even if other methods are used so faras the object of the present invention can be achieved. Moreover, thefilm formation method can be applied even in a case where CVD other thansputtering is used. Also, in the present embodiments, the presentinvention was applied to a method of producing an MOS device, but thepresent invention is not restricted to this and can be applied also toother devices (bipolar transistors, charge-coupled devices, etc.) otherthan an MOS device. Moreover, it can be applied also to interconnectionmaterials other than aluminum, such as copper and silver.

Since the Ti (002) crystal with which titanium and silicon are apt toreact is formed in the contact portion, a stable ohmic-contact isobtained.

Since a TiN film having an excellent TiN construction in terms of thefilm quality is formed, the barrier property is increased, and theelement reliability is improved.

The barrier property is further improved by the TiON/TiN construction.

Since the TiON is formed on the TiN, by using a TiON film having ahigher anti-reflection effect than that of the TiN, the wave effectwhich is always present in photolithography can be reduced and stableinterconnection processing becomes possible.

Since the anti-reflection film is formed by the TiON/Ti construction,the voids of the via-contacts are no longer generated, and theelectromigration (EM) durability of the via-contacts is improved.

Since the TiN/TiN or TiON/TiN construction is basically the same as thatof the conventional TiN single layer formation method, no great changeis made in the process of fabrication and the amount of capitalinvestment can be kept down.

What is claimed is:
 1. A semiconductor interconnect apparatus,comprising:a substrate; an interlayer insulation film disposed on asurface of the substrate; an adhesion layer of titanium disposed on asurface of the interlayer insulation film, the adhesion layer oftitanium having a crystal lattice direction of (002); a titanium nitridefilm disposed on a surface of the adhesion layer of titanium, thetitanium nitride film having a crystal lattice direction of (111); atitanium oxynitride film disposed on a surface of the titanium nitridefilm; a titanium film disposed on a surface of the titanium oxynitridefilm; and an aluminum film disposed on a surface of the titanium film.2. A semiconductor interconnect apparatus as claimed in claim 1, whereinthe titanium nitride film has high density and low resistivity.
 3. Asemiconductor interconnect layer, comprising:a substrate; a firsttitanium film disposed on a surface of the substrate; a first aluminumfilm disposed on a surface of the first titanium film; a titaniumnitride film disposed on a surface of the first aluminum film, thetitanium nitride film has high density and low resistivity and has acrystal lattice direction of (111); a titanium oxynitride film disposedon a surface of the titanium nitride film; an interlayer insulation filmdisposed on a surface of the titanium oxynitride film; a second titaniumfilm disposed on a surface of the interlayer insulation film; and asecond aluminum film disposed on a surface of the second titanium film.